Lens unit

Abstract

The invention provides a lens unit capable of limiting movement of a second lens barrel in an optical axis direction without applying a load to a lens accommodated in a first lens barrel. The lens unit (1) includes a lens (L1), a lens (L2) disposed on an image side (X2) of the lens (L1), a first lens barrel (3) accommodating the lens (L1), and a second lens barrel (4) accommodating the lens (L2) and held on an inner peripheral side of the first lens barrel (3). The first lens barrel (3) is provided with a protruding section (102) that protrudes from the image-side portion toward the inner peripheral side. The second lens barrel (4) is provided with: an image-side stepped section (224) that comes into contact with the protruding section (102) from the object side (X1); and a lens barrel fixing section (245) that comes into contact with the protruding section (102) from the image side (X2) and sandwiches the protruding section (102) between the lens barrel fixing section (245) and the image-side stepped section (224).

Description

Technical Field

[0001] The present invention relates to a lens unit comprising: a first lens barrel for accommodating a first lens, and a second lens barrel disposed on the image side of the first lens on the inner circumferential side of the first lens barrel for accommodating a second lens. Background Technology

[0002] Such a lens unit is described in Patent Document 1. In this document, the first lens barrel has stepped portions on the left and right sides of the middle of its inner peripheral surface in the optical axis direction. The stepped portion includes a receiving portion facing the object side and a small-diameter portion facing radially inward on the image side of the supported portion. On the other hand, the second lens barrel (lens retaining ring) has stepped portions on its outer peripheral surface. The stepped portion includes a supported portion facing the image side and a opposing portion opposite to the small-diameter portion. By having the supported portion in close contact with the receiving portion in the optical axis direction, the second lens barrel is held on the inner peripheral side of the first lens barrel in a position in the optical axis direction.

[0003] Additionally, the lens unit includes a cover mounted on the object-side end portion of the first lens barrel. The diameter of the cover is larger than that of the first lens barrel, and it is screwed into the external thread formed on the object-side end portion of the first lens barrel, thereby being fixed to the first lens barrel. The end portion of the cover on the object side has a pressing portion protruding inwardly. When the cover is screwed into the first lens barrel, the pressing portion abuts against the outer peripheral edge of the first lens from the object side, preventing the first lens from falling off towards the object side. Furthermore, the pressing portion, via the first lens and the lens assembly housed in the second lens barrel, causes the second lens barrel to abut against the receiving portion of the first lens barrel.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-203907 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] In a structure such as Patent Document 1, which uses a pressing part that contacts the first lens to restrict the movement of the second lens barrel in the direction of the optical axis, there is a possibility that the first lens is subjected to a load via the pressing part.

[0009] In view of the above problems, the objective of the present invention is to provide a lens unit that can restrict the movement of a second lens barrel in the optical axis direction without applying a load to the lens housed in the first lens barrel.

[0010] Technical solutions adopted to solve technical problems

[0011] To address the aforementioned issues, the lens unit of the present invention comprises: a first lens; a second lens disposed on the image side of the first lens; a first lens barrel housing the first lens; and a second lens barrel housing the second lens and held on the inner circumferential side of the first lens barrel. The first lens barrel includes a protrusion extending from the image side toward the inner circumferential side, and the second lens barrel includes an object-side abutment portion abutting the protrusion from the object side, and a lens barrel fixing portion contacting the protrusion from the image side and sandwiching the protrusion between the object-side abutment portion and the protrusion.

[0012] In this invention, the protrusions of the first lens barrel are clamped from both sides in the optical axis direction by means of the object-side abutment and the lens barrel fixing part provided on the second lens barrel. Therefore, it is possible to restrict the movement of the second lens barrel in the optical axis direction without applying a load to the lenses housed in each lens barrel. In addition, since the object-side abutment of the second lens barrel abuts against the protrusions of the first lens barrel, the position of the second lens barrel relative to the optical axis direction of the first lens barrel can be defined.

[0013] In this invention, the lens barrel fixing part may be configured to include: a first plastically deformable portion that bends outwards, and a contact portion that contacts the protrusion on the outer periphery of the plastically deformable portion. That is, the lens barrel fixing part may be configured to form the first plastically deformable portion by riveting a portion of the second lens barrel outwards, and to have its front end contact portion contact the protrusion.

[0014] In this invention, the second lens barrel may be configured such that the image-side portion of its outer peripheral surface has an image-side stepped portion, the image-side stepped portion having an annular surface facing the image side and an image-side outer peripheral surface portion extending from the inner peripheral end of the annular surface toward the image side, the annular surface being the object-side abutment portion, and an image-side gap being provided radially between the image-side outer peripheral surface portion and the protrusion. With this configuration, it is possible to avoid the second lens barrel's orientation relative to the first lens barrel being determined as the second lens barrel abutting against the inner peripheral end face of the protrusion when the object-side abutment portion and the lens barrel fixing portion of the second lens barrel clamp the protrusion of the first lens barrel.

[0015] In this invention, the first lens barrel can be configured such that it has an object-side opposing portion that is radially outwardly opposite to the object-side end portion of the second lens barrel; an object-side gap is provided between the opposing surface portion that is radially opposite to the object-side opposing portion and the object-side opposing portion on the outer peripheral surface of the second lens barrel; the position of the object-side end portion of the second lens barrel is defined within the range of the object-side gap, and the position of the image-side outer peripheral surface portion is defined within the range of the image-side gap. With this configuration, the orientation of the second lens barrel relative to the first lens barrel can be defined within the range of the object-side gap and the image-side gap. Furthermore, since there are object-side gaps and image-side gaps between the first and second lens barrels, even if the second lens barrel expands due to heat or moisture absorption, its effects can be absorbed within these gaps.

[0016] In this invention, an inter-lens adhesive layer can be provided between the flange surface on the outer periphery of the image-side lens surface of the first lens and the flange portion on the outer periphery of the object-side lens surface of the second lens. This inter-lens adhesive layer seals the space between the image-side lens surface and the object-side lens surface from the outer periphery, and the inter-lens adhesive layer is elastic. This configuration prevents or suppresses the intrusion of water vapor or other substances from the outside into the space formed between the image-side lens surface and the object-side lens surface in the optical axis direction. Furthermore, if the inter-lens adhesive layer is elastic, even if the second lens barrel expands due to heat or moisture absorption, causing slight displacement of the second lens, the inter-lens adhesive layer will deform accordingly, thereby maintaining the seal of the space communicating between the first image-side lens surface and the second object-side lens surface.

[0017] In this invention, the second lens barrel, having a plate-shaped optical component, has an optical component holding portion at its image-side end portion, which includes an optical component holding portion for holding the optical component. The optical component holding portion includes an optical component mounting surface for mounting the optical component from the image side; and an optical component opposing portion from the image side to the optical component mounted on the optical component mounting surface. The optical component opposing portion includes a second plastically deformed portion bent inwards, and an opposing portion at the inner circumference of the plastically deformed portion that faces the optical component. With this configuration, the optical component held at the image-side end portion of the second lens barrel can be mechanically prevented from detaching towards the image side. Alternatively, the optical component opposing portion can be configured such that the second plastically deformed portion is formed by riveting a portion of the second lens barrel inwards, and that the opposing portion at its front end faces the optical component.

[0018] In this invention, the lens barrel fixing portion and the opposing portion of the optical component can be visually visible when viewed from the image side. If configured in this way, the riveting punch can be pressed from the image side of the second lens barrel, thereby establishing the lens barrel fixing portion and the opposing portion of the optical component.

[0019] In this invention, the first plastically deformed portion and the second plastically deformed portion can be positioned at the same height along the optical axis. The protrusion side contact surface of the protrusion contacted by the contact portion of the lens barrel fixing portion is located closer to the image side than the optical component side facing surface of the opposing portion of the optical component opposing portion. With this configuration, since the first plastically deformed portion and the second plastically deformed portion are at the same height, a riveting punch with a flat punch surface can be used to install the lens barrel fixing portion and the optical component opposing portion in one step. Furthermore, the protrusion side contact surface of the protrusion contacted by the contact portion of the lens barrel fixing portion is located closer to the image side than the optical component side facing surface of the opposing portion of the optical component opposing portion. Therefore, when using a riveting punch with a flat punch surface to install the lens barrel fixing portion and the optical component opposing portion in one step, it is possible to prevent or suppress the opposing portion of the optical component opposing portion from being pressed against the opposing optical component side facing surface, thus preventing damage to the optical component.

[0020] In this invention, the lens barrel fixing part can be configured to be located at two locations on both sides of the optical component, and the opposite parts of the optical component can be located at two locations on both sides of the optical component, but at different positions from the lens barrel fixing part.

[0021] In this invention, the lens barrel fixing part can be configured such that it extends from the second lens barrel to the outer peripheral side and is welded to the protrusion. That is, it can be configured such that the lens barrel fixing part is formed by melting a portion of the second lens barrel and extending towards the first lens barrel side, thereby being welded to the protrusion.

[0022] Invention Effects

[0023] In the lens unit of the present invention, the protrusion of the first lens barrel is sandwiched between two sides in the optical axis direction by means of the object-side abutment portion and the lens barrel fixing portion provided on the second lens barrel. Therefore, it is possible to restrict the movement of the second lens barrel in the optical axis direction without applying a load to the lenses housed in each lens barrel. In addition, since the object-side abutment portion of the second lens barrel abuts against the protrusion of the first lens barrel, the position of the second lens barrel relative to the optical axis direction of the first lens barrel can be defined. Attached Figure Description

[0024] [ Figure 1 [This is a three-dimensional view of the lens unit as seen from the object side.]

[0025] [ Figure 2 This is a three-dimensional view of the lens unit as seen from the image side.

[0026] [ Figure 3 [ ] is a cross-sectional view of the lens unit.

[0027] [ Figure 4 [ ] is an exploded three-dimensional view of the lens unit.

[0028] [ Figure 5 [ ] is a cross-sectional view of the first lens tube.

[0029] [ Figure 6 [] is a sectional view of the second unit.

[0030] [ Figure 7 [This is a stereoscopic view of the second lens tube as seen from the object side.]

[0031] [ Figure 8 This is a stereoscopic view of the lens unit during assembly, viewed from the image side.

[0032] [ Figure 9 [This is an enlarged cross-sectional view of the area near the opposite part of the optical component.]

[0033] [ Figure 10 [This is a three-dimensional view of the lens unit of the deformed example when viewed from the image side.] Detailed Implementation

[0034] Hereinafter, embodiments of the lens unit to which the present invention is applied will be described with reference to the accompanying drawings.

[0035] (Overall structure)

[0036] Figure 1 This is a perspective view of the lens unit applied to the present invention, viewed from the object side. Figure 2 This is a stereoscopic view of the lens unit when viewed from the image side. Figure 3 This is a cross-sectional view of the lens unit. Figure 3 In the text, the shapes of the lenses representing the area between the two double-dotted lines (around the optical axis) are omitted.

[0037] Figure 1 The lens unit 1 shown is used in a camera device mounted on a car or surveillance camera. For example... Figure 3As shown, the lens unit 1 comprises, from the object side to the image side, a lens L1 (first lens), a lens L2 (second lens), a lens L3 (third lens), a lens L4 (fourth lens), a lens L5 (fifth lens), and a lens L6 (sixth lens). Lens L6 is a conjoined lens, comprising, from the object side to the image side, an object-side lens L61 and an image-side lens L62. Furthermore, the lens unit 1 comprises a first lens barrel 3 serving as a lens barrel 2 and a second lens barrel 4 held on the inner periphery of the first lens barrel 3. Lens L1 is housed in the first lens barrel 3. Lenses L2 to L6 are housed in the second lens barrel 4. The outer diameter of lens L1 is larger than the outer diameter of lenses L2 to L6.

[0038] like Figure 1 As shown, lens L1 and first lens barrel 3 constitute the first unit 50. Figure 4 As shown, lenses L2 to L6 and the second lens barrel 4 constitute the second unit 60. In the following description, the direction along the optical axis L of lens L1 is defined as the optical axis direction X. The optical axis L of lens L1 is the optical axis L of lens unit 1. The object side X1 in the optical axis direction X is the side where lens L1 is located, and the image side X2 is the side where lens L6 is located.

[0039] (Optical system)

[0040] like Figure 1 , Figure 3 As shown, lens L1 is a meniscus lens with a convex shape on the object side X1. (As...) Figure 3 As shown, lens L1 has an annular flange surface 11 extending in a direction orthogonal to the optical axis L on the outer periphery of the image-side lens surface L1a. A first O-ring 7 is disposed on the image-side X2 of the flange surface 11 of lens L1. Lens L1 is made of glass or resin. In this example, it is made of glass.

[0041] Lens L2 includes a lens body 13 having a lens surface and a flange 14 surrounding the lens body 13. The lens body 13 is a meniscus lens with a convex shape on the object side X1. The object-side lens surface L2a of lens L2 protrudes towards the object side X1. An annular protrusion 15 protruding towards the object side X1 is provided on the end face of the flange 14 on the object side X1. The annular protrusion 15 has an annular opposing surface 15a at its front end, which is opposite to the flange surface 11 of lens L1 in the optical axis direction X. An inter-lens adhesive layer 12 is provided between the flange surface 11 of lens L1 and the opposing surface 15a of the second lens. The inter-lens adhesive layer 12 is elastic.

[0042] Lens L3 includes a lens body 16 having a lens surface and a flange 17 surrounding the lens body 16. The lens body 16 is a meniscus lens with a convex shape on the image side X2. An annular fitting portion 18 protruding toward the object side X1 is provided on the end face of the flange 17 on the image side X2. The fitting portion 18 includes a fitting portion conical surface 18a surrounding the optical axis L and inclined toward the image side X2 toward the inner peripheral side, and a fitting portion end face 18b extending perpendicularly to the optical axis L from the end of the fitting portion conical surface 18a on the image side X2 toward the inner peripheral side.

[0043] An elastic member is disposed between lens L2 and lens L3 in the optical axis direction X. The elastic member is a second O-ring 8. The second O-ring 8 is compressed in the optical axis direction X between the flange portion 14 of lens L2 and the flange portion 17 of lens L3.

[0044] Lens L4 includes a lens body portion 20 having a lens surface and a flange portion 21 surrounding the lens body portion 20. The lens surface on the object side X1 of the lens body portion 20 of lens L4 is a curved surface protruding towards the object side X1. The lens surface on the image side X2 of the lens body portion 20 has a curved surface portion protruding towards the image side X2 at its center. At the end face of the flange portion 21 on the object side X1, there is a fitted portion 22 for fitting the fitting portion 18 of lens L3. The fitted portion 22 includes a fitted portion conical surface 22a surrounding the optical axis L and inclined inward toward the image side X2, and a fitted portion end face 22b extending perpendicularly to the optical axis L from the end of the fitted portion conical surface 22a on the image side X2 toward the inward periphery. The fitted portion conical surface 18a of lens L3 and the fitted portion conical surface 22a of lens L4 are in surface contact. The mating end face 18b of lens L3 and the mated end face 22b of lens L4 are separated in the optical axis direction X. Thus, lens L3 is radially positioned relative to lens L4. Furthermore, the image-side X2 end face of the outer peripheral portion of the mating portion 18 in the flange portion 17 of lens L3 and the object-side X1 end face of the outer peripheral portion of the mated portion 22 in the flange portion 21 of lens L4 are in contact in the optical axis direction X. Therefore, lens L3 overlaps lens L4 in the optical axis direction X.

[0045] The outer diameter of lens L5 is smaller than that of lenses L2, L3, L4, and L6. Lens L5 includes a lens body 24 with a lens surface and a flange 25 surrounding the lens body 24. The lens body 24 is a biconvex lens. The image side X2 of the flange 25 is a contact portion 26 that contacts lens L6 from the object side X1. The cross-section of the contact portion 26 along the optical axis L is an arc that curves towards the object side X1 towards the outer periphery. The surface of the image side X2 of the contact portion 26 is continuous with the outer peripheral end of the lens surface 24a of the image side X2 in the lens body 24 without any height difference.

[0046] A resin support 28 is disposed radially outward of lens L5. The support 28 is annular. Here, an aperture 33 is disposed between lens L4 and lens L5. The aperture 33 is an annular sheet sandwiched between lens L4 and support 28.

[0047] The object-side lens L61 includes a lens body 35 with a lens surface and a flange 36 surrounding the lens body 35. The object-side X1 lens surface of the object-side lens L61 is a curved surface curved towards the image side X2, and the image-side X2 lens surface is a curved surface concave towards the object side X1. The flange 36 of the object-side lens L61 has a contacted portion 37 on the object side X1, which is contacted by the contact portion 26 of the lens L5. The contacted portion 37 is a conical surface extending towards the object side X1 towards the outer periphery. The contact portion 26 and the contacted portion 37 are in line contact. The flange 36 of the object-side lens L61 has an annular end face 38 perpendicular to the optical axis L on the image side X2.

[0048] The image-side lens L62 includes a lens body 40 with a lens surface and a flange 41 surrounding the lens body 40. The object-side lens surface X1 of the image-side lens L62 is a curved surface protruding towards the object-side X1, and the image-side lens surface X2 is also a curved surface protruding towards the object-side X1. The image-side lens L62 is fixed to the object-side lens L61. The outer diameter of the image-side lens L62 is smaller than the outer diameter of the object-side lens L61. Therefore, when viewed from the image side X2, the flange 36 of the object-side lens L61 includes a portion protruding outwards from the image-side lens L62.

[0049] Here, lenses L2, L3, L4, object-side lens L61, and image-side lens L62 are all made of resin. In this example, lenses L2, L3, L4, object-side lens L61, and image-side lens L62 are all made of amorphous plastic. Amorphous plastic is, for example, polycarbonate. Lens L5 is made of glass.

[0050] Additionally, lens L5 overlaps on lens L6. Lens L4 overlaps on lens L6 via support 28. Lens L6, lens L5, support 28, and lens L4 constitute a stack 44. Lens L3 overlaps on lens L4 in a radially positioned state by fitting it into lens L4. Lens L2 is held in the second lens barrel 4 on the object side X1 of lens L3.

[0051] Next, a plate-shaped optical component 10 is disposed on the image side X2 of lens L6. Optical component 10 is a bandpass filter. In this example, optical component 10 is an IR cutoff filter. Figure 2 As shown, the shape of the optical component 10 is rectangular when viewed from the optical axis direction.

[0052] (Mirror tube)

[0053] Figure 4 This is an exploded stereoscopic view of lens unit 1. Figure 5 This is a cross-sectional view of the first lens tube. (Example) Figure 3 As shown, the lens unit 1 includes a first lens barrel 3 serving as a lens barrel 2, and a second lens barrel 4 held on the inner periphery of the first lens barrel 3. Both the first lens barrel 3 and the second lens barrel 4 are made of resin. Lens L1 is housed in the first lens barrel 3. Lenses L2 to L6 and a support 28 are housed in the second lens barrel 4. The second lens barrel 4 is held on the inner periphery of the first lens barrel 3.

[0054] (First lens barrel and lens L1)

[0055] like Figure 4 As shown, the first lens barrel 3 is cylindrical. The first lens barrel 3 is located on the outer periphery of lenses L2, L3, L4, support 28, lens L5, lens L6, and the second lens barrel 4. Figure 5 As shown, the first lens barrel 3 has an object-side stepped portion 101 at its object-side X1 end on its inner peripheral surface. Additionally, the first lens barrel 3 has an annular protrusion 102 at its image-side X2 end. Furthermore, the first lens barrel 3 has an intermediate stepped portion 103 between the object-side stepped portion 101 and the protrusion 102 on its inner peripheral surface.

[0056] The object-side stepped portion 101 includes: a support surface 105 facing the object side X1, an annular wall surface 106 extending from the inner peripheral end of the support surface 105 toward the image side X2, and a peripheral wall surface 107 extending from the outer peripheral end of the support surface 105 toward the object side X1. In the first lens barrel 3, the object side X1 of the object-side stepped portion 101 is a first lens receiving portion 108 that receives the outer peripheral portion of the lens L1. The second lens barrel 4 is disposed on the inner peripheral side of the annular wall surface 106.

[0057] The first lens receiving portion 108 includes: a peripheral wall surface 107, a support surface 105, and a riveting portion 109. For example... Figure 3 As shown, the peripheral wall surface 107 faces the lens L1 from the radially outer side. The support surface 105 faces the flange surface 11 of the lens L1 from the image side X2. The riveting portion 109, when viewed from the optical axis direction X along the optical axis L of the lens L1, overlaps with the support surface 105 and abuts against the lens L1 from the object side X1. The riveting portion 109 is a plastically deformed portion provided by means of heat riveting or the like, by bending the end of the first lens barrel 3 from the object side X1 inward to the inner peripheral side. Here, the outer peripheral portion of the lens L1 is disposed between the support surface 105 and the riveting portion 109. The first O-ring 7 is disposed between the end face of the image side X2 of the lens L1 and the support surface 105 and is compressed in the optical axis direction X.

[0058] like Figure 4 , Figure 5As shown, multiple locations along the circumference of the annular wall 106 are provided with object-side protrusions 110 that project radially inward. In this example, the object-side protrusions 110 are provided at equal angular intervals at three locations along the circumference. The object-side protrusions 110 are object-side opposing portions that are radially outward opposite to the object-side end portion of the second lens barrel 4 (positioning surface 223 described later) for positioning the second lens barrel 4 in the radial direction.

[0059] like Figure 5 As shown, the protrusion 102 includes: an annular object-side annular surface 111 facing the object side X1, an image-side annular surface 112 facing the image side X2, and an inner peripheral end surface 113 extending in the optical axis direction X and connecting the inner peripheral end of the object-side annular surface 111 and the inner peripheral end of the image-side annular surface 112. Figure 4 As shown, on the object-side annular surface 111, there are multiple ribs 114 that protrude toward the object side X1 and extend in an arc shape in the circumferential direction. In this example, the ribs 114 are arranged at equal angular intervals at three locations in the circumferential direction.

[0060] Here, rib 114 is an image-side positioning part used to position the second lens barrel 4 in the optical axis direction X. Additionally, the inner peripheral end face 113 is an image-side opposing part that is radially outward opposite to the image-side portion of the second lens barrel 4 (the image-side outer peripheral surface portion 227 described later) for radial positioning of the second lens barrel 4. Figure 2 As shown, the image-side annular surface 112 of the protrusion 102 is located closer to the object-side X1 than the end face 115 of the image-side X2 of the first lens barrel 3. On the image-side annular surface 112, there are four circumferentially spaced arcuate ribs 119 extending in the circumferential direction.

[0061] like Figure 5 As shown. The intermediate stepped portion 103 includes: an annular stepped flange surface 116 facing the object side X1, and an annular stepped wall surface 117 extending from the inner peripheral end of the stepped flange surface 116 toward the image side X2. In this example, the intermediate stepped portion 103 is provided with notches 118 extending in the optical axis direction X at multiple circumferential locations, which circumferentially divide the stepped flange surface 116 and the stepped wall surface 117. The notches 118 are provided at equal angular intervals at three circumferential locations. Therefore, the intermediate stepped portion 103 is divided into three circumferentially by the notches 118. The bottom surface of the notches 118 is an annular wall surface 106 extending from the inner peripheral end of the support surface 105 toward the image side X2, which has a conical shape in which the inner diameter of the portion where the intermediate stepped portion 103 is provided decreases toward the image side X2. The annular wall 106 reaches the end of the outer peripheral side of the annular surface 111 on the object side of the protrusion 102 in the inner peripheral surface of the first lens tube 3.

[0062] Here, when the second lens barrel 4 is held within the first lens barrel 3, the first lens barrel 3 and the second lens barrel 4 do not contact each other radially between the object-side protrusion 110 and the protrusion 102 in the optical axis direction X. That is, the first lens barrel 3 and the second lens barrel 4 have a radial gap between the object-side protrusion 110 and the protrusion 102 in the optical axis direction X. The first lens barrel 3 and the second lens barrel 4 do not contact each other radially when the object-side protrusion 110 is closer to the object side X1 and the image side X2 is closer to the protrusion 102.

[0063] Next, as Figure 5 As shown, the first lens barrel 3 has three stepped portions 121, 122, and 123 on the object-side portion of its outer peripheral surface, and the outer diameter of these three stepped portions decreases in a stepped manner towards the image-side X2. Furthermore, these stepped portions have external threads 124 on the image-side X2. However, the shape of the outer peripheral surface of the first lens barrel 3 is not limited to this. For example, the outer peripheral surface of the first lens barrel 3 may sometimes be integrally provided with a frame for mounting the lens unit 1 to an external machine.

[0064] (Second lens barrel and lenses L2 to L6, optical components)

[0065] Figure 6 This is a sectional view of the second unit 60. Figure 6 The cross-section is about the axis L and Figure 3 The second unit 60 was cut off at an angle that differed by 90°. Figure 7 This is a stereoscopic view of the second lens tube 4 as observed from the object side X1. Figure 8 This is a stereoscopic view of lens unit 1 during assembly, viewed from the image side X2. Figure 9 This is an enlarged cross-sectional view of the area near the optical component holding part 204. (See image) Figure 6 As shown, the second lens barrel 4 houses lenses L2, L3, L4, L5, support 28, and lens L6 on its inner circumferential side. Additionally, the second lens barrel 4 holds optical component 10 at its image-side X2 end.

[0066] The second lens barrel 4 has an object-side stepped portion 201 at its object-side X1 end on its inner peripheral surface. Additionally, the second lens barrel 4 has an image-side protrusion 202 protruding inwards at its image-side X2 end. Furthermore, the second lens barrel 4 has a positioning stepped portion 203 located between the object-side stepped portion 201 and the image-side protrusion 202 on its inner peripheral surface, and closer to the image-side protrusion 202 than the object-side stepped portion 201. Moreover, the second lens barrel 4 has an optical component holding portion 204 for holding the optical component 10 at the image-side X2 of the image-side protrusion 202.

[0067] The object-side stepped portion 201 includes: a seat surface 205 facing the object side X1, an annular wall surface 206 extending from the inner peripheral end of the seat surface 205 toward the image side X2, and a peripheral wall surface 207 extending from the outer peripheral end of the seat surface 205 toward the object side X1. The annular wall surface 206 is a conical surface whose inner diameter decreases toward the image side X2. In the second lens barrel 4, the object side X1 of the object-side stepped portion 201 is a second lens receiving portion 208 that receives the outer peripheral portion of the lens L2.

[0068] The second lens receiving portion 208 includes: a peripheral wall surface 207, a seat surface 205, and a riveting portion 209. The peripheral wall surface 207 is a conical surface that slopes outward from the seat surface 205 toward the object side X1. Figure 7 As shown, the peripheral wall surface 207 has multiple circumferentially spaced portions, each having a fitting protrusion 210A that presses against the lens L2. In this example, the fitting protrusions 210A are arranged at equal angular intervals in six circumferential locations. The inner circumferential end of the fitting protrusion 210A has a pressing surface 210a parallel to the optical axis L. The multiple fitting protrusions 210A are pressed against the lens L2 housed in the second lens housing 208 from the radially outer side via the pressing surface 210a, thereby positioning the lens L2 radially. The seat surface 205 faces the image-side X2 end face of the flange portion 14 of the lens L2 from the image side X2. The riveting portion 209, when viewed from the optical axis direction X, overlaps with the seat surface 205 and abuts against the lens L2 from the object side X1. The riveting portion 209 is a plastically deformed portion provided by heat riveting or the like by bending the object-side X1 end of the second lens barrel 4 inwards towards the inner circumferential side. Here, as Figure 6 As shown, the annular protrusion 15 provided on the flange portion 14 of the lens L2 protrudes further toward the object side X1 than the riveting portion 209 on the inner circumferential side of the riveting portion 209.

[0069] The annular wall 206 of the object-side stepped portion 201 extends towards the image side X2 and reaches the positioning stepped portion 203. For example... Figure 7 As shown, on the annular wall surface 206, from the image side X2 towards the object side X1, there are sequentially arranged fitting protrusions 210B, fitting protrusions 210C, fitting protrusions 210D, and guide protrusions 220 at predetermined intervals. These fitting protrusions 210B-210D and guide protrusions 220 protrude inwards from multiple circumferentially spaced portions. The fitting protrusions 210B-210D have a pressing surface parallel to the optical axis L at their inner circumferential ends. The guide protrusions 220 have a guide surface parallel to the optical axis L at their inner circumferential ends.

[0070] like Figure 6As shown, the positioning step portion 203 is located on the image-side portion of the inner circumference of the second lens barrel 4. The positioning step portion 203 includes: an annular stepped positioning surface 215 facing the object side X1, and a stepped peripheral wall surface 216 extending from the inner circumferential end of the stepped positioning surface 215 toward the image side X2. The annular wall surface 206 of the object-side stepped portion 203 extends toward the image side X2 and reaches the outer circumferential end of the stepped positioning surface 215. Figure 7 As shown, on the stepped positioning surface 215, there are multiple positioning ribs 217 that protrude toward the object side X1 and extend in an arc shape in the circumferential direction.

[0071] like Figure 6 As shown, the flange 36 of the object-side lens L61 of lens L6 is mounted on the positioning rib 217. Thus, the laminate 44, composed of lens L6, lens L5, support 28, and lens L4, is housed in the second lens barrel 4 in a positioned state along the optical axis X. Furthermore, fitting protrusions 210B, 210C, and 210D, provided on the annular wall surface 206, are pressed radially outward onto lens L6, support 28, and lens L4, respectively. Thus, the laminate 44 is positioned radially. The image-side lens L62 of lens L6, which is joined to the object-side lens L61, is disposed on the inner circumferential side of the stepped peripheral wall surface 216. The stepped peripheral wall surface 216 is radially spaced apart from the image-side lens L62.

[0072] Here, as Figure 3 As shown, lens L3 is fitted into the fitted portion 22 of lens L4 via its fitting portion 18, thereby being positioned radially. Furthermore, lens L3 is positioned in the optical axis direction X by overlapping onto lens L4. The guide protrusion 220 is a component used to guide lens L3 toward lens L4; when lens L3 is radially positioned by lens L4, the guide protrusion 220 is radially spaced from lens L3.

[0073] The second O-ring 8 is disposed radially inside the annular wall 206 of the object-side of the plurality of guide protrusions 220 and the object-side stepped portion 201. For example... Figure 6 As shown, the second O-ring 8 is compressed in the optical axis direction X between the lens L2 and the lens L3 housed in the second lens housing 208.

[0074] Next, the second lens barrel 4 has an annular positioning surface 223 at its object-side X1 end on its outer peripheral surface. The positioning surface 223 is located radially outward of the second lens receiving portion 208. The positioning surface 223 is a surface parallel to the optical axis L, facing radially outward. When the second lens barrel 4 is received within the inner peripheral side of the first lens barrel 3, the positioning surface 223 is opposite to the object-side protrusion 110 (object-side opposing portion) of the first lens barrel 3. Figure 3As shown, there is an object-side gap C1 between the object-side protrusion 110 and the positioning surface 223.

[0075] In addition, such as Figure 6 As shown, the second lens barrel 4 has an image-side stepped portion 224 on its outer peripheral surface. The image-side stepped portion 224 includes an annular surface 225 facing the image side X2, an object-side outer peripheral surface portion 226 extending from the outer peripheral end of the annular surface 225 towards the object side X1, and an image-side outer peripheral surface portion 227 extending from the outer peripheral end of the annular surface 225 towards the image side X2. The image-side outer peripheral surface portion 227 is connected to the outer peripheral end of the image-side annular end face 213 of the second lens barrel 4. Furthermore, the outer peripheral surface of the second lens barrel 4 has an intermediate stepped portion 228 located between the positioning surface 223 and the image-side stepped portion 224, and close to the positioning surface 223. The intermediate stepped portion 228 includes an annular surface 229 facing the image side X2. The object-side outer peripheral surface portion 226 of the image-side stepped portion 224 reaches the inner peripheral end of the annular surface 229. The image-side stepped portion 224 (annular surface 229) is the object-side contact portion that abuts against the protrusion 102 of the first lens barrel 3 from the object side X1.

[0076] like Figure 3 As shown, when the second lens barrel 4 is housed within the inner circumference of the first lens barrel 3, the image-side stepped portion 224 is mounted on multiple ribs 114 of the protrusion 102 of the first lens barrel 3. The inner circumferential end face 113 (image-side opposite portion) of the protrusion 102 of the first lens barrel 3 faces the image-side outer circumferential surface portion 227. An image-side gap C2 is provided between the inner circumferential end face 113 and the image-side outer circumferential surface portion 227. The image-side gap C2 is larger than the object-side gap C1. The image-side gap C2 is 10 μm or more and 15 μm or less on one side of the optical axis L.

[0077] like Figure 2 As shown, an optical component holding portion 204 is provided on the image-side annular end face 213 of the second lens barrel 4. The optical component holding portion 204 includes an optical component mounting surface 231 that surrounds the central hole of the second lens barrel 4 in the central portion of the image-side annular end face 213 (see reference). Figure 3The optical component holding portion 204 includes an optical component opposing portion 232, which extends from the image-side annular end face 213 to the inner peripheral side of one pair of guide ribs 232 (1) and faces the optical component 10 placed on the optical component mounting surface 231. The optical component opposing portion 233 includes a plastic deformation portion 234 (second plastic deformation portion) that bends from the image-side X2 end face of one pair of guide ribs 232 (1) toward the inner peripheral side and faces the optical component 10 placed on the optical component mounting surface 231 from the image-side X2. The optical component opposing portion 233 includes a plastic deformation portion 234 (second plastic deformation portion) that bends from the image-side X2 end face of the guide rib 232 toward the inner peripheral side and an opposing portion 235 that faces the optical component 10 on the inner peripheral side of the plastic deformation portion 234. The opposing portion 235 faces the outer peripheral edge portion of the optical component 10.

[0078] like Figure 8 As shown, the opposing portion 233 of the optical component is formed by riveting the optical component at the image-side X2 end face of a pair of guide ribs 232(1) provided in a set with a riveting allowance 241 to the inner peripheral side to form a plastically deformable portion 234, and the opposing portion 235 at its front end is opposite to the optical component 10. A gap is provided between the opposing portion 235 and the optical component 10 in the optical axis direction X. The optical component 10 is fixed to the second lens barrel 4 by adhesive applied to its outer peripheral side while being held in the optical component holding portion 204. While being held in the optical component holding portion 204, the front end portions of the four corners of the optical component 10 protrude from the second lens barrel 4 to the outer peripheral side and overlap with the protrusion 102 of the first lens barrel 3 when viewed from the optical axis direction X. Here, the image-side annular surface 112 of the protrusion 102 is located at a position closer to the object side X1 than the optical component 10. Therefore, the optical component 10 does not contact the first lens barrel 3.

[0079] (Eyepiece tube fixing part)

[0080] Here, as Figure 2 As shown, among the four guide ribs 232 surrounding the image-side annular end face 213 from all sides, another pair of guide ribs 232(2) are provided with lens barrel fixing parts 245 for fixing the first lens barrel 3 and the second lens barrel 4. The lens barrel fixing parts 245 contact the protrusion of the first lens barrel 3 from the image side X2 when the second lens barrel 4 is housed within the inner circumference of the first lens barrel 3. Figure 2 , Figure 3 As shown, the lens barrel fixing part 245 includes: a plastic deformation portion 246 (first plastic deformation portion) that bends towards the outer periphery of the end face of the image side X2 of the guide rib 232, and a contact portion 247 that contacts the protrusion on the outer periphery of the plastic deformation portion 246. Figure 8As shown, the lens barrel fixing part 245 is formed by riveting the lens barrel fixing riveting allowance 242 of the end face of the image side X2 of a pair of guide ribs 232 (2) provided in another set to the inner circumference to form a plastic deformation part 246, and the opposite part 235 at its front end is opposite to the optical component 10.

[0081] Here, when viewing the lens unit 1 from the image side X2, the lens barrel fixing part 245 and the optical component opposing part 233 are visible to the naked eye. Furthermore, along the optical axis X of the optical axis L, the plastically deformed portion 234 of the optical component opposing part 233 and the plastically deformed portion 246 of the lens barrel fixing part 245 are at the same height. The lens barrel fixing part 245 is respectively provided at two locations on both sides of the optical component 10, and the optical component opposing part 233 is respectively provided at two locations on both sides of the optical component 10, but at different positions from the lens barrel fixing part 245.

[0082] (Fixing the first and second lens tubes)

[0083] When fixing the first lens barrel 3 and the second lens barrel 4, lenses L2 to L6 are first held in the second lens barrel 4. In this state, the optical component 10 is not held in the optical component holding portion 204 of the second lens barrel 4. Furthermore, in this state, as... Figure 8 As shown, a pair of optical component fixing riveting allowances 241 and a pair of lens barrel fixing riveting allowances 242 located at the image side X2 end of the second lens barrel 4 are not riveted.

[0084] Next, the second lens barrel 4 is held in place of the first lens barrel 3. That is, the second lens barrel 4 is inserted into the inner circumference of the first lens barrel 3 from the object side X1. When inserting the second lens barrel 4 into the first lens barrel 3, the outer circumferential surface portion 227 of the image-side stepped portion 224 of the second lens barrel 4 is first inserted into the inner circumferential side of the protrusion 102 of the first lens barrel 3. Next, the annular surface 225 of the image-side stepped portion 224 of the second lens barrel 4 is placed on the plurality of ribs 114 of the protrusion 102 of the first lens barrel 3. In addition, in parallel with this, the object-side end portion (positioning surface 223) of the second lens barrel 4 is inserted into the inner circumferential side of the object-side stepped portion 101 of the first lens barrel 3.

[0085] Here, as Figure 3As shown, an image-side gap C2 is provided between the inner circumferential end face 113 (image-side opposite portion) of the protrusion 102 of the first lens barrel 3, which is used to position the first lens barrel 3 and the second lens barrel 4 in the radial direction, and the image-side outer circumferential surface portion 227 of the image-side stepped portion 224 of the second lens barrel 4. Additionally, an object-side gap C1 is provided between the object-side protrusion 110 (object-side opposite portion) of the annular wall surface 106 of the object-side stepped portion 101 of the first lens barrel 3, which is provided for positioning the first lens barrel 3 and the second lens barrel 4 in the radial direction, and the positioning surface 223 of the object-side end portion of the second lens barrel 4. Furthermore, the image-side gap C2 is larger than the object-side gap C1. That is, when the second lens barrel 4 is inserted into the first lens barrel 3 from the object side X1, the image-side gap C2 between the image-side outer peripheral surface portion 227 of the image-side stepped portion 224 of the first inserted second lens barrel 4 is larger than the object-side gap C1 between the positioning surface 223 of the second lens barrel 4 and the object-side protrusion 110 of the first lens barrel 3. Therefore, it is easier to insert the second lens barrel 4 into the first lens barrel 3.

[0086] Furthermore, an image-side gap C2 is provided between the inner peripheral end face 113 (image-side opposite portion) of the protrusion 102 of the first lens barrel 3 and the image-side outer peripheral surface portion 227 of the image-side stepped portion 224 of the second lens barrel 4. An object-side gap C1 is provided between the object-side protrusion 110 (object-side opposite portion) of the annular wall surface 106 of the object-side stepped portion 101 of the first lens barrel 3 and the positioning surface 223 of the object-side end portion of the second lens barrel 4. Moreover, there is a radial gap between the object-side protrusion 110 (object-side opposite portion) and the protrusion 102 in the optical axis direction X of the first lens barrel 3 and the second lens barrel 4. Therefore, the second lens barrel 4 is not in a state of being completely positioned in all radial directions, but is positioned on the first lens barrel 3 with a very slight wobble.

[0087] Next, the first lens barrel 3 and the second lens barrel 4 are held in a clamped position with the object side X1 facing downwards (see reference). Figure 8 Then, the optical component 10 is placed in the optical component holding portion 204 of the second lens barrel 4. Here, the image-side annular surface 112 of the protrusion 102 of the first lens barrel 3 is located closer to the object side X1 than the optical component mounting surface 231 of the second lens barrel 4. Therefore, the corner of the optical component 10 protruding from the second lens barrel 4 to the outer periphery does not contact the first lens barrel 3.

[0088] Then, a riveting punch with a flat punch surface is brought close to the first lens barrel 3 and the second lens barrel 4 from above (image side X2) to rivet a pair of optical component fixing riveting allowances 241 and a pair of lens barrel fixing riveting allowances 242 located at the image side X2 end of the second lens barrel 4. Here, as Figure 8As shown, the surfaces on opposite sides of the optical axis L of the pair of optical component fixing riveting allowances 241 are formed as inclined surfaces 241a that slope outward from the front end toward the guide rib 232. Therefore, by approaching the second lens barrel 4 with a riveting punch in the optical axis direction X, the pair of optical component fixing riveting allowances 241 form an optical component opposing portion 233 having a plastic deformation portion 234 that bends inward and an opposing portion 235 that faces the optical component 10 on the inner periphery of the plastic deformation portion 234. Furthermore, the surfaces of the pair of lens barrel fixing riveting allowances 242 on the optical axis L side are formed as inclined surfaces 242a that slope inward from the front end toward the guide rib 232. Therefore, by using a riveting punch, the pair of lens barrel fixing riveting allowances 242 form a lens barrel fixing portion 245 having a plastic deformation portion 246 that bends outward and a contact portion 247 that contacts the protrusion 102 on the outer periphery of the plastic deformation portion 246.

[0089] Here, as Figure 9 As shown, the height dimension H1 between the optical component mounting surface 231 and the image-side X2 end face of the guide rib 232 is longer than the thickness dimension D1 of the optical component 10. In addition, the end face 119a (protrusion-side contact surface) of the arc rib 119 is located closer to the image-side X2 than the image-side surface 10a (optical component-side opposing surface) of the optical component 10 opposite to the opposing portion 235 of the optical component opposing portion 233. Therefore, when a riveting punch with a flat punch surface is used to rivet a pair of optical component fixing riveting allowances 241 and a pair of lens barrel fixing riveting allowances 242, the lens barrel fixing riveting allowances 242 are plastically deformed to the outer periphery, and the contact portion 247 at its front end contacts the end face 119a of the arc rib 119 of the first lens barrel 3. However, a gap is provided between the opposite portion 235 at the front end of the optical component fixing riveting allowances 241 that are plastically deformed to the inner periphery and the optical component 10 in the optical axis direction X.

[0090] When the riveting is completed, the second lens barrel 4 is positioned such that the protrusion 102 of the first lens barrel 3 is sandwiched between the annular surface 225 of the image-side stepped portion 224 and the lens barrel fixing portion 245. Therefore, the second lens barrel 4 is fixed to the first lens barrel 3. Furthermore, the optical component 10 is mechanically prevented from detaching from the second lens barrel 4 towards the image side X2 by the optical component opposing portion 233. Then, adhesive is applied to the outer periphery of the optical component 10. As a result, the optical component 10 is fixed to the optical component holding portion 204.

[0091] Next, the first lens barrel 3 and the second lens barrel 4 are reversed vertically. Then, adhesive is applied to the opposing surface 15a of the flange portion 14 of the lens L2, which is held in the second lens barrel 4. Additionally, the first O-ring 7 is placed on the support surface 105 of the first lens barrel 3. Then, the lens L1 is supported on the support surface 105 of the first lens barrel 3 via the first O-ring 7. Next, a riveting portion 109 bent inwards is formed at the end portion of the object side X1 of the first lens barrel 3. When the riveting portion 109 is formed, the first O-ring 7 is compressed in the optical axis direction X between the end face of the image side X2 of the lens L1 and the support surface 105 of the first lens barrel 3. Here, the inter-lens adhesive layer 12, after the adhesive has hardened, seals the space V between the image side lens surface L1a of the lens L1 and the object side lens surface L2a of the lens L2 in the optical axis direction X on the outer periphery. The inter-lens adhesive layer 12 is elastic.

[0092] (Effects)

[0093] The lens unit 1 in this example includes: a lens L1; a lens L2 disposed on the image side X2 of the lens L1; a first lens barrel 3 housing the lens L1; and a second lens barrel 4 housing the lens L2 and held on the inner circumferential side of the first lens barrel 3. The first lens barrel 3 includes a protrusion 102 protruding from the image side towards the inner circumferential side. The second lens barrel 4 includes an image-side stepped portion 224 abutting against the protrusion 102 from the object side X1, and a lens barrel fixing portion 245 contacting the protrusion 102 from the image side X2 and sandwiching the protrusion 102 between the image-side stepped portion 224. Therefore, the movement of the second lens barrel 4 in the optical axis direction X can be restricted without applying a load to the lenses housed in each lens barrel. In addition, since the image-side stepped portion 224 of the second lens barrel 4 abuts against the protrusion 102 of the first lens barrel 3, the position of the second lens barrel 4 relative to the optical axis direction X of the first lens barrel 3 can be defined.

[0094] Here, the lens barrel fixing part 245 includes: a plastic deformation portion 246 that bends outward and a contact portion 247 that contacts the protrusion 102 on the outer peripheral side of the plastic deformation portion 246. Therefore, it can be configured such that the lens barrel fixing part 245 forms the plastic deformation portion 246 by riveting a part of the second lens barrel 4 outward and the contact portion 247 at its front end contacts the protrusion 102.

[0095] In this example, the second lens barrel 4 has an image-side stepped portion 224 on the image-side portion of its outer peripheral surface. The image-side stepped portion 224 has an annular surface 225 facing the image side X2, and an image-side outer peripheral surface portion 227 (image-side opposing portion) extending from the inner peripheral end of the annular end face towards the image side X2. The annular surface 225 abuts against the protrusion 102 from the object side. Radially, an image-side gap C2 is provided between the image-side outer peripheral surface portion 227 and the inner peripheral end face 113 of the protrusion 102. Therefore, it is possible to prevent the posture of the second lens barrel 4 relative to the first lens barrel 3 from being determined to be such that the second lens barrel 4 abuts against the inner peripheral end face 113 of the protrusion 102 when the first lens barrel 3 is clamped by the image-side stepped portion 224 and the lens barrel fixing portion 245 provided on the second lens barrel 4.

[0096] Furthermore, in this example, the first lens barrel 3 has an object-side protrusion 110 (object-side opposing portion) that faces the object-side X1 end portion of the second lens barrel 4 from the radially outer side. An object-side gap C1 is provided between the positioning surface 223 (opposing surface portion) that faces the object-side protrusion 110 radially on the outer peripheral surface of the second lens barrel 4 and the object-side protrusion 110. In the radial direction, the position of the object-side X1 end portion of the second lens barrel 4 is defined within the range of the object-side gap C1, and the position of the image-side end portion is defined within the range of the image-side gap C2. Therefore, the orientation of the second lens barrel 4 relative to the first lens barrel 3 can be defined within the ranges of the object-side gap C1 and the image-side gap C2.

[0097] That is, the second lens barrel 4 is positioned radially between a state in which a portion of the outer periphery of its object-side X1 end portion contacts the object-side protrusion 110 of the first lens barrel 3, and a state in which its end portion of the object-side X1 is separated by a gap of C1 across the entire circumference without contacting the object-side protrusion 110. Therefore, the radial wobble of the object-side X1 end portion of the second lens barrel 4 is a wobble of the object-side gap C1, which is extremely small. Furthermore, the image-side X2 end portion of the second lens barrel 4 is positioned on the inner circumference side of the first lens barrel 3, within the image-side gap C2. That is, the second lens barrel 4 is positioned between a state in which a portion of the outer periphery of its image-side X2 end portion contacts the image-side outer peripheral surface portion 227 of the first lens barrel 3, and a state in which its end portion of the image-side X2 is separated by a gap of C2 across the entire circumference without contacting the image-side outer peripheral surface portion 227. Therefore, the radial wobble of the image-side X2 end portion of the second lens tube 4 is a wobble of the image-side gap C2, which is extremely small.

[0098] Furthermore, two portions of the second barrel, separated along the optical axis X, are positioned between the object-side X1 end portion and the image-side portion. Therefore, the tilt of the optical axis of the lens L2 held in the second barrel 4 relative to the optical axis L of the lens L1 held in the first barrel 3 is suppressed. Moreover, the object-side gap C1 between the object-side X1 end portion of the second barrel 4 near the lens L1 and the first barrel 3 is smaller than the image-side gap C2 between the image-side portion of the second barrel 4 and the first barrel 3. Consequently, the wobble of the object-side X1 is suppressed more than that of the image-side X2. Therefore, a significant shift in the optical axis L of the lens L1 held in the first barrel 3 and the optical axis of the lens L2 held in the second barrel 4 can be suppressed.

[0099] Furthermore, since there is an object-side gap C1 and an image-side gap C2 between the first lens barrel 3 and the second lens barrel 4, even if the second lens barrel 4 expands due to heat or moisture absorption, its effects can be absorbed within these gaps C1 and C2. That is, according to this example, the second lens barrel 4 is not in a fully radially positioned state, but is positioned on the first lens barrel 3 in a state of potential wobbling. Therefore, even if the deformation of the first lens barrel 3 due to heat or moisture absorption differs from that of the second lens barrel 4 due to differences in shape, thickness, or substrate, the difference in deformation can be absorbed by wobbling (object-side gap C1 and image-side gap C2). Thus, when the first and second lens barrels deform due to heat or moisture absorption, the load applied from the first lens barrel 3 to the second lens barrel 4 and the load applied from the second lens barrel 4 to the first lens barrel 3 can be prevented or suppressed.

[0100] In this example, an inter-lens adhesive layer 12 is provided between the outer peripheral portion (flange 14) of the image-side lens surface L1a of lens L1 and the outer peripheral portion (opposite surface 15a) of the object-side lens surface L2a of lens L2. The inter-lens adhesive layer 12 seals the space V formed between the image-side lens surface 1a of lens L1 and the object-side lens surface L2a of lens L2 from the outer peripheral side. The inter-lens adhesive layer 12 is elastic. Therefore, it is possible to prevent or suppress the intrusion of water vapor or the like into the space V formed in the optical axis direction X between the image-side lens surface 1a of lens L1 and the object-side lens surface L2a of lens L2. Here, because the inter-lens adhesive layer 12 is elastic, even if the second lens barrel 4 expands due to heat, causing a slight displacement of lens L2, the inter-lens adhesive layer 12 will deform along with the displacement, thus maintaining the seal of the space V.

[0101] Next, this example has a plate-shaped optical component 10. The second lens barrel 4 has an optical component holding portion 204 at its image-side X2 end portion for holding the optical component 10. The optical component holding portion 204 has an optical component mounting surface 231 for mounting the optical component 10 from the image-side X2, and an optical component facing portion 233 that faces the optical component 10 mounted on the optical component mounting surface 231 from the image-side X2. Therefore, it is possible to mechanically prevent the optical component 10 held at the image-side X2 end portion of the second lens barrel 4 from falling off in the optical axis direction X.

[0102] In this example, the optical component opposing portion 233 includes: a plastically deformable portion 234 that bends inwards, and an opposing portion 235 that faces the optical component 10 on the inner peripheral side of the plastically deformable portion 234. Therefore, it can be configured such that the optical component opposing portion 233 forms the plastically deformable portion 234 by riveting a portion of the second lens barrel 4 inwards, and that the opposing portion 235 at its front end faces the optical component 10.

[0103] In this example, when viewing the lens unit 1 from the image side X2, the lens barrel fixing part 245 and the optical component opposing part 233 are visible to the naked eye. Therefore, the riveting punch can be pressed from the image side X2 of the second lens barrel 4 to install the lens barrel fixing part 245 and the optical component opposing part 233.

[0104] In this example, along the optical axis direction X of the optical axis L, the plastically deformed portion 246 of the lens barrel fixing part 245 and the plastically deformed portion 234 of the optical component opposing part 233 are at the same height. Therefore, a riveting punch with a flat punch surface can be used to install the lens barrel fixing part 245 and the optical component opposing part 233 in one step. In addition, the protrusion-side contact surface (end face 119a of the arc rib 119) of the protrusion 102 contacted by the contact portion 247 of the lens barrel fixing part 245 is located closer to the image side X2 than the optical component-side opposing surface (the image side X2 surface of the optical component 10) opposite to the opposing portion 235 of the optical component opposing part 233. Therefore, when the lens barrel fixing part 245 and the optical component opposing part 233 are installed in one step, it is possible to prevent or suppress the opposing portion 235 of the optical component opposing part 233 from being pressed against the image side X2 surface of the opposing optical component 10, which could lead to damage to the optical component 10.

[0105] (Modified Example)

[0106] Figure 10 This is a three-dimensional view of the lens unit in the deformed example, viewed from the image side. For example... Figure 10 As shown, in the lens unit 1A of this example, the lens barrel fixing part 245 extends from the second lens barrel 4 to the outer peripheral side and is welded to the protrusion 102.

[0107] In this case, among the four guide ribs 232 surrounding the image-side annular end face 213 from all sides, a second lens barrel-side welding allowance protruding in the optical axis direction X is provided on a pair of guide ribs 232 (2) in another set that does not have a riveting allowance 241 for fixing optical components. Additionally, a first lens barrel-side welding allowance protruding in the image-side X2 is provided on the end face of the arcuate rib 119 provided on the image-side annular end face 112 of the protrusion 102 of the first lens barrel 3. When fixing the first lens barrel 3 and the second lens barrel 4, the second lens barrel 4 is first inserted into the first lens barrel 3, and the image-side stepped portion 224 of the second lens barrel 4 is placed on the plurality of ribs 114 of the protrusion 102 of the first lens barrel 3. Then, from the image-side X2 of the first lens barrel 3 and the second lens barrel 4, heat is used to melt the welding allowance of the second lens barrel 4 towards the outer periphery, while simultaneously welding it to the first lens barrel-side welding allowance of the first lens barrel 3.

[0108] Even so, the second lens barrel 4 also includes: an image-side stepped portion 224 that abuts against the protrusion 102 from the object side X1, and a lens barrel fixing portion 245 that contacts the protrusion 102 from the image side X2. Since the image-side stepped portion 224 and the lens barrel fixing portion 245 provided on the second lens barrel 4 sandwich the protrusion 102 of the first lens barrel 3 from both sides in the optical axis direction X, it is possible to restrict the movement of the second lens barrel 4 in the optical axis direction X without applying a load to the lenses housed in each lens barrel. In addition, since the image-side stepped portion 224 of the second lens barrel 4 abuts against the protrusion 102 of the first lens barrel 3, it is possible to define the position of the second lens barrel 4 relative to the optical axis direction X of the first lens barrel 3.

[0109] Here, the technology can be configured as follows.

[0110] (1) A lens unit comprising: a first lens; a second lens disposed on the image side of the first lens; a first lens barrel for housing the first lens; and a second lens barrel for housing the second lens and being held on the inner peripheral side of the first lens barrel, the first lens barrel having: a protrusion protruding from the image side to the inner peripheral side, the second lens barrel having: an object-side abutting portion abutting the protrusion from the object side, and a lens barrel fixing portion contacting the protrusion from the image side and sandwiching the protrusion between the object-side abutting portion and the protrusion.

[0111] (2) The lens unit according to (1), wherein the lens barrel fixing part includes: a first plastic deformation portion that bends outward and a contact portion that contacts the protrusion on the outer peripheral side of the plastic deformation portion.

[0112] (3) According to the lens unit of (2), wherein the second lens barrel has an image-side stepped portion on the image side of its outer peripheral surface, the image-side stepped portion having: an annular surface facing the image side, and an image-side outer peripheral surface portion extending from the inner peripheral end of the annular surface toward the image side, the annular surface being the object-side abutment portion, and an image-side gap being provided between the image-side outer peripheral surface portion and the protrusion in the radial direction.

[0113] (4) The lens unit according to (3), wherein the first lens barrel has: an object-side opposing portion that is radially opposite to the object-side end portion of the second lens barrel, and an object-side gap is provided in the outer peripheral surface of the second lens barrel between the opposing surface portion that is radially opposite to the object-side opposing portion and the object-side opposing portion, wherein the position of the object-side end portion of the second lens barrel is defined within the range of the object-side gap in the radial direction, and the position of the image-side outer peripheral surface portion is defined within the range of the image-side gap.

[0114] (5) The lens unit according to any one of (1) to (4), wherein an inter-lens adhesive layer is provided between a flange surface located on the outer peripheral side of the image-side lens surface of the first lens and a flange portion located on the outer peripheral side of the object-side lens surface of the second lens, the inter-lens adhesive layer sealingly forming the space between the image-side lens surface and the object-side lens surface from the outer peripheral side, the inter-lens adhesive layer being elastic.

[0115] (6) The lens unit according to any one of (3) to (4), wherein it has a plate-shaped optical component, and the second lens barrel has an optical component holding portion for holding the optical component at the end portion on the image side, the optical component holding portion having: an optical component mounting surface for mounting the optical component from the image side; and an optical component opposing portion from the image side and opposite to the optical component mounted on the optical component mounting surface, the optical component opposing portion having a second plastic deformation portion bent inwardly, and an opposing portion on the inner circumferential side of the plastic deformation portion and opposite to the optical component.

[0116] (7) The lens unit according to (6), wherein, when viewed from the image side, the lens barrel fixing part and the opposing part of the optical component are visible to the naked eye.

[0117] (8) The lens unit according to (6) or (7), wherein, in the direction along the optical axis, the first plastic deformation portion and the second plastic deformation portion are at the same height position, and the protrusion side contact surface of the protrusion contacted by the contact portion of the lens barrel fixing portion is located closer to the image side than the optical component side facing surface of the opposing portion of the opposing optical component.

[0118] (9) The lens unit according to any one of (6) to (8), wherein the lens barrel fixing part is respectively disposed at two locations on both sides of the optical component, and the opposite parts of the optical component are respectively disposed at two locations on both sides of the optical component and at positions different from the lens barrel fixing part.

[0119] (10) The lens unit according to any one of (6) to (9), wherein the lens barrel fixing portion extends from the second lens barrel to the outer peripheral side and is welded to the protrusion.

[0120] Explanation of reference numerals in the attached figures

[0121] 1, 1A… Lens unit in this example, 2… Lens barrel, 3… First lens barrel, 4… Second lens barrel, 7… First O-ring, 8… Second O-ring, 10… Optical component, 10a… Image side surface, 11… Flange surface, 12… Inter-lens adhesive layer, 13… Lens body, 14… Flange, 15… Annular protrusion, 15a… Opposite surface, 16… Lens body, 17… Flange, 18… Fitting part, 18a… Fitting part conical surface, 18b… Fitting part end face, 20… Lens body, 21… Flange, 22… Fitted part, 22a… Fitted part conical surface, 22b… Fitted part end face, 24… Lens body, 24a… Lens surface, 25… Flange, 26… Contact part, 28… Support, 35… Lens body 36…Flange, 37…Contacted portion, 38…Annular end face, 40…Lens body, 41…Flange, 44…Laminated body, 50…First unit, 60…Second unit, 101…Object-side stepped portion, 102…Protrusion, 103…Intermediate stepped portion, 105…Support surface, 106…Annular wall surface, 107…Peripheral wall surface, 108…First lens receiving portion, 109…Riveting portion, 110…Object-side protrusion, 111…Object-side annular surface, 112…Image-side annular surface, 113…Image-side inner wall surface, 114…Rib, 115…End face, 116…Stepped flange surface, 117…Stepped wall surface, 118…Notch, 119…Circular arc rib, 119a…End face, 121, 122, 123…Step 124…external thread, 201…object-side stepped portion, 202…image-side protrusion, 203…positioning stepped portion, 204…optical component holding portion, 205…seat surface, 206…annular wall surface, 207…peripheral wall surface, 208…second lens receiving portion, 209…riveting portion, 210a…pressing surface, 210A~210D…fitting protrusion, 213…image-side annular end face, 215…step portion positioning surface, 216…step portion peripheral wall surface, 217…positioning rib, 220…guide protrusion, 223…positioning surface, 224…image-side stepped portion, 225…annular surface, 226…object-side outer peripheral surface portion, 227…image-side outer peripheral surface portion, 228…intermediate stepped portion, 229…annular surface, 231…optical component 232…Guide rib, 233…Optical component opposite part, 234…Plastic deformation part (second plastic deformation part), 235…Opposite part, 241…Riveting allowance for fixing optical components, 241a…Inclined surface, 242…Riveting allowance for fixing lens barrel, 242a…Inclined surface, 245…Lens barrel fixing part, 246…Plastic deformation part (first plastic deformation part), 247…Contact part, 250…Inter-lens adhesive layer, C1…Object-side gap, C2…Image-side gap, D1…Thickness dimension of optical component, H1…Height dimension of guide rib, L1~L6…Lens, L1a…Image-side lens surface, L2a…Object-side lens surface, L61…Object-side lens, L62…Image-side lens, V…SpaceX…optical axis direction,

Claims

1. A lens unit, characterized in that, include: First lens; The second lens is disposed on the image side of the first lens; The first lens tube houses the first lens; as well as The second lens barrel houses the second lens and is held on the inner circumferential side of the first lens barrel. The first lens barrel includes a protrusion that extends from the image side towards the inner peripheral side. The second lens barrel includes: an object-side abutting portion that abuts against the protrusion from the object side, and a lens barrel fixing portion that contacts the protrusion from the image side and sandwiches the protrusion between the object-side abutting portion and the protrusion.

2. The lens unit according to claim 1, characterized in that, The lens barrel fixing part includes: a first plastic deformation portion that bends outward and a contact portion that contacts the protrusion on the outer peripheral side of the first plastic deformation portion.

3. The lens unit according to claim 2, characterized in that, The second lens tube has an image-side stepped portion on the image-side part of its outer peripheral surface. The image-side stepped portion has: an annular surface facing the image side, and an image-side outer peripheral surface portion extending from the inner peripheral end of the annular surface toward the image side. The annular surface is the side contact portion of the object. In the radial direction, an image-side gap is provided between the image-side outer peripheral surface portion and the protrusion.

4. The lens unit according to claim 3, characterized in that, The first lens barrel has an object-side opposing portion that is radially outwardly opposite to the object-side end portion of the second lens barrel. An object-side gap is provided between the opposing surface portion that is radially opposite to the object-side portion and the object-side portion on the outer peripheral surface of the second lens barrel. In the radial direction of the second lens barrel, the position of the object-side end portion is defined within the range of the object-side gap, and the position of the image-side outer peripheral surface portion is defined within the range of the image-side gap.

5. The lens unit according to claim 1, characterized in that, An inter-lens adhesive layer is provided between the flange surface on the outer periphery of the image-side lens surface of the first lens and the flange portion on the outer periphery of the object-side lens surface of the second lens. The inter-lens adhesive layer seals the space between the image-side lens surface and the object-side lens surface from the outer peripheral side. The inter-lens adhesive layer is elastic.

6. The lens unit according to claim 2, characterized in that, It has plate-shaped optical components. The second lens barrel includes an optical component holding portion at its image-side end. The optical component holding portion includes: an optical component mounting surface for mounting the optical component from the image side; and an optical component opposing portion from the image side opposite to the optical component mounted on the optical component mounting surface. The optical component has the following features: a second plastically deformed portion that bends inwards, and a corresponding portion on the inner periphery of the plastically deformed portion that is opposite to the optical component.

7. The lens unit according to claim 6, characterized in that, When viewed from the image side, the lens barrel fixing part and the opposing part of the optical component are visible to the naked eye.

8. The lens unit according to claim 7, characterized in that, Along the optical axis, the first plastic deformation portion and the second plastic deformation portion are at the same height. The protruding side contact surface of the protrusion that is contacted by the contact portion of the lens barrel fixing part is located closer to the image side than the optical component side facing surface that is opposite to the opposing portion of the optical component opposing part.

9. The lens unit according to claim 6, characterized in that, The lens barrel fixing parts are respectively located at two positions on both sides of the optical component. The optical components are respectively disposed at two locations on both sides of the optical components, and at positions different from the lens barrel fixing part.

10. The lens unit according to claim 1, characterized in that, The lens barrel fixing part extends from the second lens barrel to the outer peripheral side and is welded to the protrusion.

Images